Analysis of yield-attributing traits for high-yielding wheat lines in southwestern Japan

Development of wheat cultivars that achieve high yields despite the short growing season is essential for increasing wheat production in southwestern Japan. The objectives of this study were to assess the genetic progress in grain yield and to clarify yield-attributing traits of high-yielding wheat lines in southwestern Japan. We conducted field experiments for two growing seasons (2012–2013 and 2013–2014) using three commercial wheat cultivars (Shiroganekomugi, Chikugoizumi, and Iwainodaichi) and four high-yielding wheat lines including Hakei W1380 developed in southwestern Japan. In an ancillary field experiment, we compared a commercial cultivar, Shiroganekomugi, and a high-yielding line, Hakei W1380, in the 2014–2015 season. Across the two seasons, grain yield of high-yielding lines was generally higher than commercial cultivars. Hakei W1380 achieved the highest grain yield across the two seasons, and successfully produced more than 900 g m^?2 in the 2013–2014 season. Correlation analysis showed that recent yield progress of wheat lines in southwestern Japan was derived from enhanced biomass production and grain number m^?2. Larger numbers of grains m^?2 in high-yielding lines than in commercial cultivars were associated with higher crop growth rate at the pre-anthesis stage, and therefore higher spike dry weight m^?2 at anthesis. Genotypic differences in crop growth rate from jointing to anthesis resulted mainly from differences in leaf area index. These results indicate that further improvements in grain yield in southwestern Japan could be achieved by increasing the amount of radiation intercepted at the pre-anthesis stage and grain number m^?2.     

Effect of salinity on growth and accumulation of organic and inorganic solutes in the leguminous plants Alhagi pseudoalhagi and Vigna radiata

The response of two leguminous plants Alhagi pseudoalhagi and Vigna radiata to seawater salinity was studied over a period of 30 d. The growth of Vigna radiata was markedly and gradually reduced by increasing salinity levels, whereas that of Alhagi pseudoalhagi was promoted at 9.1 and 16.2 dS m^-1 salinity but then was slightly reduced at 28.2 dS m^-1 salinity. These results indicate that Alhagi pseudoalhagi belongs to the group of halophytic plants. Seawater salinity caused changes in the membrane permeability measured as electrolyte leakage in both plants. Alhagi pseudoalhagi maintained a lower membrane permeability than Vigna radiata. With increasing salinity levels, the membrane permeability decreased in Alhagi pseudoalhagi, whereas, in Vigna radiata it slightly increased at 9.1 dS m^-1. The leaf water potential and the osmotic potential decreased in both plants along with the seawater salinity levels. However, the turgor potential and osmotic adjustment in Alhagi pseudoalhagi were maintained at a higher level than in Vigna radiata. The contributions of organic and inorganic solutes to the osmotic adjustment differed: Alhagi pseudoalhagi achieved osmotic adjustment through Cl^- and Na⁺ uptake from the substrate, while the contribution of K⁺, Ca²⁺, and organic solutes to the osmotic adjustment was limited. These results suggest that the differences in salt tolerance between Alhagi pseudoalhagi and Vigna radiata can not be due to differences in specific-ion effects, but may be related to some factors involved in membrane permeability and osmotic adjustment.     

Comparison of nutritional and antinutritional factors in soybean and fababean seeds with or without cortex

The composition and contents of nutritional factors such as proteins, lipids, carbohydrates, fibers, amino acids, and antinutritional factors such as trypsin inhibitors, phytic acid, and tannins were compared in soybean and fababean seeds with emphasis placed on the nutritional improvement of the seeds by cortex removal. Protein hydrolysis analysis for both whole seeds and seed with cortex removed revealed the presence of a large amount of lysine, arginine, aspartic acid, glutamic acid, glycine, and leucine while these seeds contained a low level of tryptophan, cystine, and methionine. Some antinutritional factors such as trypsin inhibitors, phytic acid, and tannins were detected in soybean and fababean seeds: phytic acid content and trypsin inhibitor activity were higher in soybean seeds than in fababean seeds while the difference in the tannin content was less pronounced. It was found that most of the tannins occurred in the cortex of the soybean and fababean seeds. Tannins are polyphenolic compounds that readily form indigestible complexes with proteins and other macromolecules under specific environmental conditions. By removal of the cortex, tannins were almost completely eliminated without changes in the protein composition and amino acids. From these results, it is assumed that since soybean and fababean seeds contained a high concentration of antinutritional factors in the cortex such as tannins, the utilization of the legume seeds after removal of all of the cortex is suitable for human diet or industrial products.     

Nutrio-physiological studies on the tomato plant IV. Source-sink relationship and structure of the source-sink unit

In tomato plants the source exceeds the sink. This conclusion is arrived at from the following facts: (a) The net assimilation rate Increases by a partial removal of leaves and decreases by a partial or complete removal of fruits, and (b) the young developing vegetative organs, such as the apex of the stem or the lateral buds, do not consume a large amount of photosynthates because these are capable of photosynthesizing from early stages of development.

Except for several leaves at the base of the stem which send their photosynthates to the roots, a tomato plant is composed of several units, each of which is composed of three leaves, a truss and a bud, This unit is the source-sink unit and the photosynthates of the leaves of a unit go preferentially to the sinks within the unit. However, this source-sink unit is not an absolute one. There is an inter-units translocation of photosynthates and the extent of it depends on the condition of the plant.     

Bacterial Contamination of Stethoscope Chest Pieces and the Effect of Daily Cleaning

Background

Stethoscopes are a potential source of nosocomial infection for hospitalized humans, a phenomenon not previously studied in companion animals.

Objectives

To determine if daily cleaning of stethoscope chest pieces reduces bacterial contamination between cleanings.

Animals

Client‐owned dogs and cats.

Methods

Prospective observational study. In phase 1, bacterial cultures were obtained from the chest pieces of 10 participant stethoscopes once weekly for 3 weeks. In phase 2, stethoscopes were cleaned daily and 2 culture samples were obtained once weekly, immediately before and after cleaning with 70% isopropyl alcohol, for 3 weeks.

Results

Daily cleaning eliminated bacteria immediately after each cleaning (P = .004), but did not reduce the rate of positive cultures obtained before cleaning in phase 2. Cultures were positive for 20/30 (67%) samples during phase 1 and 18/30 (60%) obtained before daily cleaning during phase 2. Recovered organisms included normal skin flora, agents of opportunistic infections, and potential pathogens. The only genus that was repeatedly recovered from the same stethoscope for 2 or more consecutive weeks was Bacillus sp.

Conclusions and Clinical Importance

Daily cleaning was highly effective at removing bacteria, but provided no reduction in precleaning contamination. Cleaning stethoscopes after use on dogs or cats infected with pathogenic bacteria and before use on immunocompromised animals should be considered.     

Evaluation of dry matter production and yield in early-sown wheat using near-isogenic lines for the vernalization locus Vrn-D1

ABSTRACT

Wheat (Triticum aestivum L.) grain yield is predicted to decrease in the future because of an increase in air temperature globally. To clarify the effects of the vernalization response gene in wheat to warmer winters, we compared dry matter production and grain yield between spring wheat ‘Asakazekomugi’ and its winter-type near-isogenic line (NIL) carrying different alleles of the vernalization response gene Vrn-D1 under early-, standard-, and late-sowing conditions. Under early-sowing conditions, dry matter production of the NIL carrying the winter allele of Vrn-D1, named Asa (Vrn-D1b), exceeded that of ‘Asakazekomugi’ from mid-March (after stem elongation in Asa (Vrn-D1b)) when the temperatures rose. Tiller number and leaf area index under early-sowing conditions were consistently higher in Asa (Vrn-D1b) than in ‘Asakazekomugi’ from mid-March onward. It was suggested that the early-sown ‘Asakazekomugi’ could not effectively absorb solar radiation to produce dry matter because of the acceleration of stem elongation caused by the Vrn-D1 gene during the cold season. The grain yield of Asa (Vrn-D1b) with early sowing was higher than with standard sowing. In contrast, the grain yield of ‘Asakazekomugi’ was lower in the early-sown crop than in the crop sown at the standard date. These results suggested that the higher grain yield of Asa (Vrn-D1b) than that of ‘Asakazekomugi’ under early-sown conditions could be due to Asa (Vrn-D1b) maintaining high dry matter production after the jointing stage by suppressing acceleration of growth caused by warm conditions after sowing.     

Purification and characterization of polyphenol oxidase from cauliflower (Brassica oleracea L.)

Polyphenol oxidase (PPO) of cauliflower was purified to 282-fold with a recovery rate of 8.1%, using phloroglucinol as a substrate. The enzyme appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The estimated molecular weight of the enzyme was 60 and 54 kDa by SDS-PAGE and gel filtration, respectively. The purified enzyme, called phloroglucinol oxidase (PhO), oxidized phloroglucinol (K(m) = 3.3 mM) and phloroglucinolcarboxylic acid. The enzyme also had peroxidase (POD) activity. At the final step, the activity of purified cauliflower POD was 110-fold with a recovery rate of 3.2%. The PhO and POD showed the highest activity at pH 8.0 and 4.0 and were stable in the pH range of 3.0-11.0 and 5.0-8.0 at 5 °C for 20 h, respectively. The optimum temperature was 55 °C for PhO and 20 °C for POD. The most effective inhibitor for PhO was sodium diethyldithiocarbamate at 10 mM (IC(50) = 0.64 and K(i) = 0.15 mM), and the most effective inhibitor for POD was potassium cyanide at 1.0 mM (IC(50) = 0.03 and K(i) = 29 μM).     

Expression of seed storage proteins responsible for maintaining kernel traits and wheat flour quality in common wheat under heat stress conditions

Heat stress during grain filling has been documented to decrease wheat grain yield and quality in arid regions worldwide. We studied the effect of heat stress on wheat flour quality in heat tolerant cultivars to define the effects of heat stress on flour quality and to identify germplasm combining traits for heat tolerance and good flour quality. We studied the kernel phenotypic traits, the expression of seed storage proteins (SSPs), and the resulting flour quality under heat and normal conditions. Under heat stress, all cultivars yielded narrow-shaped seeds, and increased protein contents as compared to the control plants grown under normal conditions. The specific sedimentation values used to estimate the gluten quality varied between cultivars. We identified cultivars that could maintain good flour quality under heat stress conditions: ‘Imam’, which possessed the Glu-D1d allele responsible for the suitable bread-making; ‘Bohaine’, which displayed high expression level of SSPs; and ‘Condor’, which possessed slight variations in the ratio of each SSP under heat stress conditions. Combining the desirable traits from these cultivars could yield a wheat cultivar with heat tolerance and good flour quality.     

Waxy wheat as a functional food for human consumption

Waxy wheat (Triticum aestivum L.), a type of wheat that was first developed in Japan, produces grain amylopectin. I carried out three researches. Firstly, using Japanese adults, we carried out sensory evaluation of three types of mochi (a dumpling-like cake made of steamed and pounded grains) prepared from waxy wheat, normal wheat and waxy rice, and demonstrated that waxy wheat mochi had low adhesiveness and had the greatest ease of swallowing among the samples tested. Secondly, using the members of the JSDR (the Japanese Society of Dysphagia Rehabilitation) who attended the annual meeting, we performed another texture evaluations between waxy wheat and waxy rice mochi. The respondents reported waxy wheat mochi was less sticky and thus easier to chew and swallow than waxy rice mochi.